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Biomedical subjects

N Hashimoto

Publications and source records attributed to N Hashimoto.

At least 649 records · Page 36Linked to original sources
PubMed1985

Histologic changes in rat brain tissue caused by neodymium-yttrium aluminum garnet laser irradiation. II. Cerebellum.

Histologic changes after neodymium-yttrium aluminum garnet laser irradiation were evaluated in the rat cerebellum. Irradiation of 60 W (corresponds to 45.2 W/mm2) to the posterior fossa was dangerous even in adult rats, although this value was safe for the rat cerebral hemisphere as previously reported. The histologic changes caused by neodymium-yttrium aluminum garnet laser irradiation were similar to those caused by thermal energies. To the adult rat cerebellum, 45 W (35.2 W/mm2) can safely be applied. For the further use of the neodymium-yttrium aluminum garnet laser in neurosurgery, our findings should be taken into consideration.

Animals↗
PubMed1985

Modulation of insulin action by fasting: a study using a phosphodiesterase activation system in rat fat cells.

Fat cells from control and 72 h fasted rats were incubated with increasing concentrations of insulin at 37 degrees C for 10 min. A crude microsomal fraction from these cells was used for the determination of phosphodiesterase activity. Specific activities of the enzyme in fat cells from the fasted rats were higher at overall insulin concentrations. In the fasted rats the curve shifted to the left at the lower concentrations of insulin and the half-maximal dose was lower than in the controls. Specific binding of insulin to the receptor was increased at the lower concentrations of insulin in fat cells from the fasted rats and Scatchard analysis of the data revealed that the change was due to an increase in binding affinity rather than that in receptor number per cell. Therefore, it is feasible that there is a good correlation with alteration of insulin sensitivity and insulin binding. The net amount of maximal response to insulin assessed as enzyme activity per cell was markedly decreased with fasting, however, this seems to be due to a decrease in absolute amount of the enzyme per cell. Since the maximal activation of the enzyme expressed as a percent of the basal remained unchanged, the steps between insulin receptor and the phosphodiesterase may not be altered under these conditions.

Adipose Tissue↗
PubMed1985

A method for systematic purification from bovine plasma of six vitamin K-dependent coagulation factors: prothrombin, factor X, factor IX, protein S, protein C, and protein Z.

A systematic purification scheme is presented for the isolation of six vitamin K-dependent coagulation factors from bovine plasma in a functionally and biochemically pure state. The vitamin K-dependent proteins concentrated by the ordinary barium citrate adsorption were first separated into four fractions, fractions A, B, C, and D, by DEAE-Sephadex A-50 chromatography. From the pooled fraction A, protein S, factor IX, and prothrombin were purified by column chromatography on Blue-Sepharose CL-6B. Heparin-Sepharose chromatography of the pooled fraction B provided mainly pure factor IX, in addition to homogeneous prothrombin. A high degree of resolution of protein C and prothrombin from the pooled fraction C was obtained with a Blue-Sepharose column. This dye-ligand chromatographic procedure was also very effective for the separation of protein Z and factor X contained in the pooled fraction D. Thus, these preparative procedures allowed high recovery of milligram and gram quantities of six vitamin K-dependent proteins from 15 liters of plasma in only two chromatographic steps, except for protein S, which required three (the third step was rechromatography on Blue-Sepharose CL-6B).

Amino Acids↗
PubMed1985

The pathological significance of Langerhans cells in oral cancer.

The functional role of Langerhans cells (LCs) in oral cancer was studied, based on a quantitative analysis of LCs in squamous cell carcinomas arising from the tongue. LCs were identified by their positiveness for S100-protein and other cytological characters based on PAP method. LCs increased in number in the cancer region and showed an intimate relationship with lymphocytes in terms of their number and distribution. Moreover, in those cases with many LCs, clusters consisting of LCs and lymphocytes were often found to combine into "hydropic degeneration-like" lesions as seen in allergic disease such as dermal lichen planus. These findings, as well as the review of literature, suggested some immunological role of LCs in oral carcinoma.

Carcinoma, Squamous Cell↗
PubMed1985

Antiplatelet aggregators inhibit development of stress ulcers in Sprague-Dawley rats.

Antiplatelet aggregators such as sulfinpyrazone (10 mg/kg), ticlopidine (200 mg/kg), and pyridine (0.1 mg/kg) significantly inhibited the degree of gastric ulceration in Sprague-Dawley rats subjected to cold restraint stress. The inhibition of platelet aggregation and that of microthrombus formation were evident in rats given antiplatelet aggregating drugs and exposed to cold stress. Therefore, platelet aggregation does play an important role in stress ulcer formation, and drugs which inhibit this aggregation should be given greater attention as to possible clinical application for treatment of stress ulcers.

Animals↗
PubMed1985

A case of one-kidney hypertension: contrasting effects of angioplasty and treatment with captopril.

A patient with hypertension is shown to have both a renal artery stenosis due to fibromuscular dysplasia and a hypoplastic contralateral kidney, a condition comparable to that of the one-kidney Goldblatt hypertension. Both blood volume and plasma renin activity were increased. Blood pressure was lowered either by an angiotensin II analog or by captopril. Secretion of excess renin was observed only from the stenotic kidney. A 4-week period of captopril treatment was accompanied by an acute, reversible deterioration of renal function. Transluminal angioplasty corrected the abnormalities in renin and in blood volume and has kept blood pressure and renal function normal for over 2 years.

Adult↗
PubMed1985

[Effect of MCI-2016 (bifemelane hydrochloride) on cerebral ischemia following ligation of both common carotid arteries in Mongolian gerbils].

Cerebral protective effect of MCI-2016 and influence of age on survival time in the cerebral ischemic model induced by bilateral-carotid-arterial ligation in male Mongolian gerbils were studied. Of all animals (6 to 40 weeks old), the mean survival time of the immature group (6 to 7 weeks) was long (3.6 hr), but variable, and that of the 10 to 40 weeks group was relatively stable (1.9-2.4 hr), but that of the older group (30-40 weeks) inclined to be reduced. Effects of drugs on this model were studied in 10 to 15 weeks old male Mongolian gerbils. The mean survival time in the control groups was 2.3-2.4 hr. After a single administration of MCI-2016 at doses of 25 mg/kg, i.p., and 100 mg/kg, p.o., the mean survival time were 8.1 and 6.4 hr, respectively. In these cases, some animals survived over 12 hr, while no animals surviving over 12 hr were observed in the control group. In this model, animals showed severe neurological symptoms. This, however, tended to be depressed by the administration of MCI-2016 at a dose of 25 mg/kg, i.p., which was observed early after ligation. A cerebral metabolic activator, Ca-hopantenate, slightly increased the survival time at a dose of 100 mg/kg, i.p., and a cerebral vasodilator, ifenprodil, was not effective. Subsequently, consecutive administration of MCI-2016 at a dose of 25 and 50 mg/kg, p.o., was more effective than a single administration of MCI-2016 at each dose. The mechanism for the cerebral protective effect of MCI-2016 was discussed.

Administration, Oral↗
PubMed1985

[Effects of 4-(o-benzylphenoxy)-N-methylbutylamine hydrochloride (MCI-2016, bifemelane hydrochloride) on spontaneous motor activity under different experimental conditions].

Effects of MCI-2016 on SMA changes were examined under several experimental conditions (normal conditions, hypoxia and head injury). Under normal conditions, MCI-2016 showed a significant increase of SMA after single administration of 12 mg/kg, i.p. Other doses (12.5-50 mg/kg, p.o. and 3-6 mg/kg, i.p.) of MCI-2016 were without significant effect. Under the same condition, MCI-2016 produced a dose-dependent increase of SMA after repeated doses of 12.5 to 50 mg/kg, p.o. (9-10 days administrations). After 5 days repeated administration, MCI-2016 significantly improved the decreased SMA due to hypoxia (rats) at 50 to 100 mg/kg, p.o. Furthermore, the drug also improved the decreased spontaneity due to head injury (mice) at 50 to 400 mg/kg, p.o. These improving effects of MCI-2016 were superior to those of Ca-hopantenate. The SMA increasing effect of MCI-2016 (12 mg/kg, i.p.) was antagonized more strongly by phenoxybenzamine than by haloperidol. In addition, the drug was shown to be rather antagonistic to the effects of anticholinergic agents. These effects may indicate the existence of qualitative differences between MCI-2016 and methamphetamine in the SMA increasing actions. It is also suggested that MCI-2016 may exhibit the above pharmacological effects through possible activation of noradrenergic and/or cholinergic mechanisms.

Animals↗
PubMed1985

Insulin resistance of fat cells from spontaneously diabetic KK mice. Analysis of insulin-sensitive phosphodiesterase.

In an attempt to determine the mechanism of insulin resistance in the presence of obesity, we examined effects of insulin on insulin-sensitive phosphodiesterase (PDE) in spontaneously diabetic KK mice. Isolated fat cells prepared from epididymal adipose tissue were incubated, with or without insulin, for 10 min. In the case of subcellular fractionation, only membrane-bound PDE was activated by insulin, as was noted in the case of rat fat cells. The specific activity was decreased in KK mice compared with control C57BL/6 mice. The dose-response curve, expressed as a percent of the maximal insulin effect, shifted to the right and the increase of ED50 indicated a decreased insulin sensitivity in the KK mice. The maximal insulin effect did not change, either when expressed as a percent of the basal enzyme activity or when expressed on a per cell basis. Specific binding of [125I]-insulin in fat cells increased in KK mice and curvilinear Scatchard plots showed an increase of the high-affinity sites. These data indicate that impairment of PDE activation in fat cells of KK mice relates to postreceptor defects and the uncoupling may result in a decreased sensitivity.

Adipose Tissue↗
PubMed1985

Blood pressure variability and hemodynamic response to stress in patients with paroxysmal elevation of blood pressure.

Blood pressure variability during 24 hours and hemodynamic response to stress were studied in essential hypertensive patients, displaying paroxysmal hypertension and pheochromocytoma-type symptoms (PH). Hemodynamics at rest, in response to mental arithmetic, bicycle ergometer exercise or the cold together with baroreflex sensitivity were not different between these patients and other essential hypertensives (EH). Average waking systolic blood pressure was lower but variabilities of both systolic and diastolic blood pressure were greater in PH than in EH. During sleep, these differences disappeared. Thus, the greater variability in blood pressure seen only in waking PH patients cannot be estimated from the hemodynamic patterns at rest and is not likely to be related to an excessive response to stress or impaired baroreflex.

Adrenal Gland Neoplasms↗
PubMed1985

Epidemiological study of hemorrhagic fever with renal syndrome related virus infection among urban rats in two islands in Tokyo Bay, Japan.

A seroepidemiological survey of hemorrhagic fever with renal syndrome (HFRS) virus infection in 403 urban rats (Rattus norvegicus) captured on two different islands in Tokyo Bay was carried out using the indirect immunofluorescent antibody (IFA) test with the SR-11 strain of HFRS virus. Antibody positive sera were detected in 99 out of 355 (27.9%) rats from the island with reclaimed ground area, but none were detected in 48 rats from the other islands. IFA titers of the positive sera varied from 16 to 4,096 (mostly 128) with a peak at 1 : 128, and antibody positive ratios were significantly higher in the small rats (less than 50 g, probably of younger age) than in the large ones. A causative agent antigenically related to HFRS virus was isolated from lung tissue of seropositive rat using Vero-E6 cells. These results revealed the existence of HFRS related virus among urban rats in the coast of Tokyo Bay, Japan.

Animals↗
PubMed1985

[Brain stem auditory evoked potentials for assessment of isolated fourth ventricle in three patients].

Isolated fourth ventricle is an untoward but interesting complication caused by the shunt procedure, which has been recognized since the introduction of CT scanning. Auditory brain stem evoked potentials (BAEPs) were recorded in a patient with isolated fourth ventricle for assessment of brain stem function. Case 1. A 9-year-old boy. He had undergone repair of the lumbosacral meningocele at birth, followed by shunting procedures, including repeated shunt revision, for hydrocephalus which subsequently developed. CT scanning on admission revealed typical findings of isolated fourth ventricle, while neurological examination disclosed no abnormalities. BAEPs on admission revealed normal waves both in amplitude and latency. This patient has been doing well without further shunting procedures. Case 2. A 17-year-old male was admitted with complaints of headache, diplopia, nystagmus and ataxic gait. He had a history of operation for radical removal of cerebellar astrocytoma and lateral ventriculo-peritoneal shunt at 9 years of age. CT scanning on admission revealed a typical isolated fourth ventricle, and fourth ventricle-peritoneal shunt was performed. Postoperative serial BAEPs revealed gradual improvement of brain-stem function. Clinically he has been symptom-free thereafter except for slight nystagmus. Case 3. A 2-year-old female suffering from hydrocephalus developed after neonatal intraventricular hemorrhage and ventriculitis. After repeated revision of a lateral ventriculo-peritoneal shunt, she was admitted in semicoma with vomiting and opisthotonic posture. CT study revealed an isolated fourth ventricle and preoperative BAEPs showed marked abnormalities. Although fourth ventricle-peritoneal shunt was performed, no remarkable change in BAEPs was obtained, and neurological deficit of considerable degree persisted.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1985

[Treatment of primary empty sella with intractable headache via the transsphenoidal approach].

Two cases of primary empty sella with intractable headache were treated via the transsphenoidal approach. One patient was a fifty-three-year-old female with right upper nasal quadrantanopsia and intractable retrobulbar pain and the other was fourty-six-year-old female with continuous retrobulbar pain with a history of transient right temporal hemianopsia. Both cases were diagnosed by metrizamide CT cisternography. They had normal endocrinological functions. They did not respond to drug therapy and were treated surgically. In each case, the dura mater of the floor of the sella was elevated with lyophilized human dura mater and bone fragments obtained during the procedure. In the former case, significant improvement of visual field defect was not obtained but the retrobulbar pain disappeared completely after the operation. In the latter case which had intractable headache for six months, the symptom disappeared just after the operation. Until now, retroorbital pain has not recurred in both cases for several months. Primary empty sella has been considered to be a benign condition except in some cases with CSF rhinorrhea or with visual disturbance. Headache which is often accompanied to primary empty sella has rarely been treated surgically because it is difficult to know whether the headache is related to the empty sella or not. Another reason may be that there is few available data concerning to the efficacy of surgical treatment. Headache caused by stretching of the dura of the floor of the sella is usually frontal or retrobulbar, continuous, profound and intractable.(ABSTRACT TRUNCATED AT 250 WORDS)

Empty Sella Syndrome↗
PubMed1985

[Estrogen-induced pituitary tumors--in relation to the changes in the pituitary gland after estrogen withdrawal].

Pituitary tumors were induced in female rats of Wistar strain by administration of estradiol valerate (E2) and the effect of estrogen withdrawal on E2-induced tumors were studied to elucidate the nature of the induced tumors. Ten mg of E2 was administered to 100 rats intraperitoneally once every 2 weeks, totally four times. Experimental animals were sacrificed at 1 week before, 2, 6, 10, and 14 weeks after stopping injection of E2. The incidence of pituitary tumor and hyperplasia (Table 1). Pituitary glands in each animals were examined and were classified into three groups, namely pituitary tumor, hyperplasia, and normal gland according to histological findings. The incidence of pituitary tumors was highest in rats sacrificed 6 weeks after E2 withdrawal. Pituitary tumors became less frequent and hyperplasias and normal glands became more frequent in rats sacrificed thereafter. Pituitary weight (Table 2, Fig. 1) Irrespective of timing of sacrifice, the weight of pituitary gland (mean +/- SE) was 134 +/- 70 mg in the group which were judged as having a pituitary tumor, 38 +/- 17 mg in the hyperplasia group, and 17 +/- 5 mg in the normal group, respectively. Pituitary weight of control rats were 12 +/- 3 mg. The tumor group had a significantly heavier pituitary weight than hyperplasia and normal groups (p less than 0.01). In each group, there was no significant difference of pituitary weights between animals sacrificed at different intervals after E2 withdrawal.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenoma↗
PubMed1985

[Clinical analysis of large and/or invasive pituitary adenomas].

To establish a more reasonable therapeutic guide line for large and/or invasive pituitary adenomas, 257 cases of pituitary adenoma were analyzed. Among 83 cases with slight or moderate suprasellar extension (Wilson's Grade II-A & B) in the pre-CT era, 57 patients were alive at the time of follow-up (mean follow-up period: 12.7 years). Death of unspecified causes other than cancer, myocardial infarction, etc. were reported in nine patients. Among 60 cases of Grade II-A & B in the post-CT era, 59 patients were alive (mean follow-up: 3.4 years). Comparing these groups, cases with huge suprasellar extension (Grade C) had much worse prognosis. Only two patients were alive among 14 cases of Group C in the pre-CT era. Seven cases of death with unspecified causes were reported. In the 13 cases of Group C in the post-CT era, 12 patients were alive but at least four of them were severely handicapped. In 10 cases with sphenoid invasion (Grade IV) in the pre-CT era, only two were alive. In the group of Grade IV in the post-CT era, one patient died and three patients were operated repeatedly. Severe complications of irradiation therapy occurred in seven patients (mean interval: 6.6 years) among 120 cases of irradiated pituitary adenomas in every category. Among six cases with histological malignancy, three were operated repeatedly; among the latter group, two patients died and the third showed intracranial metastases. The present data indicate that large and/or invasive pituitary adenomas have a pessimistic prognosis, although adenomas with mild or moderate simple suprasellar extension have fairly good prognosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenoma↗
PubMed1984

Activated B cells express receptors for, and proliferate in response to, pure interleukin 2.

In this study we investigated whether interleukin 2 (IL-2) acts on B cell proliferation and whether activated B cells express IL-2 receptors. First, the functional activity of immunoaffinity-purified or recombinant human IL-2 was studied in a B blast assay using positively selected murine surface Ig-positive cells that had been activated by lipopolysaccharide (LPS) plus anti-Ig antibodies (anti-Ig). In this assay, T cells were not detected by fluorescence-activated cell sorter analysis. It was found that both IL-2 preparations led to optimal B cell proliferation compared with supernatants obtained from murine or human spleen cells or murine cloned T helper cells. Second, we observed that the IL-2 requirement in this assay was about the same as in a proliferation assay using lectin-activated polyclonal murine Lyt-2-positive T cells. Third, analysis of the binding of radiolabeled immunoaffinity-purified IL-2 to B cells indicated that LPS plus anti-Ig-activated B cells expressed a mean of 3,500 IL-2 receptors per cell with an apparent dissociation constant of 150 pM. However, neither nonactivated B cells nor B cells activated by LPS alone exhibited significant specific IL-2 binding. The functional and the receptor data are consistent with the conclusion that IL-2 is a growth factor not only for T cells but also for B cells.

Animals↗
PubMed1984

Biotin-labeled antigen sandwich enzyme-linked immunosorbent assay (BLA-S-ELISA) for the detection of Japanese encephalitis antibody in human and a variety of animal sera.

A biotin-labeled antigen (BLA) was adapted to a sandwich enzyme-linked immunosorbent assay (S-ELISA) for detection of Japanese encephalitis (JE) antibody in a variety of animal sera. JE antigen was fixed on the wells of a microplate and became bound to the specific antibody which could react with a peroxidase-labeled avidin conjugate and azino-di-(3-ethylbenzthiazolin sulfonic acid) (ABTS) as a substrate. The BLA-S-ELISA could simultaneously detect JE antibody in all hemagglutination inhibition (HI) positive sera from man, swine, monkey, horse, cattle, rabbit, rat, mouse and pigeon by using the same reagents under the same test conditions. The antibody titers obtained by BLA-S-ELISA in human and swine sera corresponded well with HI antibody titers. The sensitivity of BLA-S-ELISA appeared to be higher for IgM antibody than for IgG antibody. Since the non-specific reaction was extremely low in BLA-S-ELISA, the cut-off titer for the assay could be set as low as 1:2.5 of serum dilution for positive antibody.

Animals↗